Pipe calipering device



June 24, 1958 w, E. BARNES 2,839,837

PIPE CALIPERING DEVICE Filed July 12, 1956 s Sheets-Sheet 1 F/'g./ A

INVENTOR. WILLIAM E; BARNES wash- Q ATTORNEY W. E. BARNES PIPE CALIPERING DEVICE s Sheets-Sheet 2 INVENTOR. WILLIAM E. BARNES B Q O, 54km ATTORNEY June 24, .1958

Filed July 12. 1956 June 24, 1958 w, E. R E 7 2,839,837 v PIPE CALIPERING DEVICE Filed July 12. 1956 s Sheets-Sheet a AT TORNEY U d St t Patm10fii 2,839,837 Patented June, 24, 1958 This. inventionfrelates to tubing ,calipers in general and morefparticularlyto calipering devices for radially sensing and registering the number and depth of pits or'depressions in the internal wall of the tubing.

'. Thediscovery of defects in tubing by'means of calipers which' radially sensethe presence and 'depthsof pits and depressions in the tubing inner Wallis known in the art and accomplished inlong strings of tubing as. explained inthe patentto Chaney et al., No. 2,518,663, issued August 15, 1950. In this and like patents the results of the calipering operation are expressed in deviations of radial measurements and are recorded within the caliper, all being self-contained These records evidencing the calipering operation indicate the location and degree of the wear or corrosion and indicate the possibility of either continued use of portions of the tubing or of salvage and replacement.

Generally, corrosion in oil well tubing and pipe lines used in the chemical and petroleum industries, for example, does not occur uniformly throughout the tubing, and some joints may be subjected to severe corrosion or pitting while others may undergo little if any corrosion. This fact is well recognized and measures are' taken to separate the usable portions of the tubing from that which is unusable. The determination of the further usefulness of oil well tubing often is made after the tubing string has been withdrawn and the tubing sections have been separated and stacked in racks.

7 Many methods of examination of the standing or racked tubing have been adopted. These methods in general include sounding the tubing lengths as by striking them sharply with a hammer, visually examining them with mirrors and lights, and by use of special instruments such as self-contained calipers as above described or with electrically operated calipers capable of indicating the internal condition of the tubing on 'an indicator or recorder mounted externally of the tubing. These methods are objectionable in greater or less degree because of the inaccuracy of the first twomethods and the labor required and costs of operation in the later methods.

It is the primary object of this invention to provide a mechanically operated caliper which will register the number and depth of pits and interior defects in the calipered length of tubing. It is a further object of this invention to provide a caliper combined with which is a registering means responsive to both the number and depth of the tubing pits and depressions. .Another object of this invention is to provide a registering mechanism for mechanically operated calipers of the contact feeler type in which the defects in the inner wall of tubing are cumulatively registereclin groups according to the-depths of the pits or depressions.

With the above objects in view, the invention resides in the novel features of construction'and-their combination which will be more particularly described in conjunction with the drawing, in which:

y'Figure-lis an elevational view inthe longitudinal position of the calipering mechanism as it appears in use.

FigurelZ is a'sectional view of the device shown' in calipering'position in a tube.

Figure 3is a sectional view of Figure 1 taken on line 3-'3 andpresented in an enlarged-scale for clarity.

Figures 4 and 5 are schematic views of'the register readings which maybe indicated, for purposes of describing the operation of the device I .Figure 6 is an alternate form of register combination, partly insection.

Figure 7 is another alternate form of register combination, partly in section.

Referring to the drawings, Figure 1 shows the calipering tool 10 horizontallypositioned as it would appear ready for operation. It is preferred to use this device in tubing lengths supported in racks, but it will be evident that it can be used in such lengths otherwise positioned for inspection. In operation, the device is not limited to horizontal operation. The calipering tool 10 has a member, .or sub, 12 for. connection with a rod or Wire line so that the tool can be pushed or pulled through tubing to be calipered. This member 12 is threaded to engage the housing of the tool as shown in Figure 2. A number 'of circumferentially spaced slots 14 in the housingpermit pivotally mounted calipering feelers 16 to extend outwardly thereof to contact the inner wall of the tubing 18. Feelers 16 are urged outwardly independently'of each other by individual springs .20 acting directly on the inwardly projecting arms of the bell-crank shaped feelers. Centering plunger 22, urged downwardly by compressed centering spring 24, also engages the inwardly projecting arms of all the feelers and operates to uniformly and resilientlypush the feelers into centering contact with the tubing innerwall.

Opposed to the effects of the centering plunger common to allfeelers and'the individually operating springs 20, the .jactuator rod ,26 is concentrically positioned for reciprocatingrnovement in the caliper housing. Spring 28 urgesthe actuator rod into operating contact with the inwardly projecting 'arms'of the feelers. Thus spring 28 is selectedto be weaker than each of the individual feeler springs 20' which it opposes in operation, so that any one of the. springs is capable of moving the attended feeler against the resistance of spring 28 when such feeler encounters a pit or depression in the tubing wall.

The 'feelerheadportion of the calipering tool de scribed above operates in accordance with the principles disclosed in the Chaney et a1. Patent No. 2,518,663 previously cited. As the caliper passes through the tubing in calipering operation, the feelers press against the tubing wall and independently move outwardly as pits,

or depressions are encountered. The actuating rod 26 reciprocate s "longitudinally of the caliper housing in response to the greatest outward movement of the feelers at any instant offoperation. Actuating rod 26 is therefore moved in reciprocating longitudinal movement relative to; the caliper housing a distance responsive to the depth of the maximum internal radial deformation encountered at any instant of circumferential contact.

Means toregister and separately accumulate the numher and extent of these reciprocal movements of actuating rod 26' is arrang'ed to attach to the feeler head portion of the caliper described above." An elongate housing '30 arranged to threadedly engage the feeler housing 10and of substantially the same diameter, positions the registerelements in operating contact with the actuating rod.'' Figure 1 shows the assembly of the feeler nansin gand register housing comprising the caliper deViCe'Ia'ndFiguresZ and 3 illustrate the elements and theiri'cobp'erationd;

T Referring to Figures- 2 and 3 I particularly, the re gisterto receive one end of actuating rod 26 for connection with the register actuating means which forms, in essence, a ratchet mechanism. Transverse apertures 34, indicated here as four in number equally spaced in the quadrants of the'cross-sectional view noted as Figure 3, are tooled in the housing 30 to mount the actuated ele ments of the ratchet-mechanism and attendant registering elements. .It will be evident that this registering means is not necessarily restricted to four registering elements. The number of such elements is restricted only by the results desired considered with the available dimensions of the device.

Each registering element shown here as a single wheel, peripherally numbered from zero to an upper limit selected through experience, is coupled to a gear wheel forming the actuated element of the ratchet means. As each register element and the attendant gear wheel differs from every other like combination in this first-described form of the device, each such element will be separately numbered. Further, it will be understood that the simplest form of registering sub-combination is shown here. It is within the ability of those versed in the art to amplify such registering mechanisms to include two or more digits for greatly amplified operation if desired.

Returning to Figures 2 and 3, the-four registering wheels 36, 38, 40 and 42 are operatively connected to the actuated elements of the ratchet means shown as gears 44, 46, 48 and 50 respectively. The digits appearing on the rims of the registering wheels and the number of teeth on the gears associated with them are relatively proportioned to respond to the operation of the actuating elements of the ratchet means. This embodiment, as distinguished from the alternate arrangements in Figures 6 and 7, differs in having gears with varied number and size of teeth for each register wheel. The elements actuating the gears are all of equal length. These actuating elements are shown in simple formin Figure 2 as leaf springs 52, 54, 56 and 58. Fastener means such as a screw 60 for the spring elementfastens each of the springs to actuating rod 26 in position to engage the respective gear elements of the ratchet. The portion of each leaf spring adjacent its respective gear is bent at a convenient angle, as shown at 62 forspring element 56, for proper operating engagement. To limit the arc of engagement of the' ratchet elements and thereby require each separate register wheel to indicate a reading within desired limits of actuating rod movements, adjustable stops like 63 and 65 are provided. Cooperating with the adjustable stops, tapers or lips such as 64; and 66 are machined adjacent each ratchet wheel assisting in lifting the spring element'from operating contact after operating engagement. Thus by adjusting the stops preliminary to operation the length of the arc of contact is lengthened or shortened thereby limiting or extending the movement of the register wheel to the desired length of travel of the actuating rod.

Finally; completing the description of the registering '4 .1 pull cable or rod and is pulled through the tubing. As

.the device moves through the tubing, the feelers 16 engage the tubing inner wall in centering and sensing relation, being urged to that position by the several springs described above. When a deformation such as a pit is encountered by any one of the feelers, the contour of the pit it traced by the feeler and the actuating rod moved accordingly. This motion is conveyed to the spring members of the ratchet means which are engaged with the gears adjacent the register wheels.

Every spring member does not, however, necessarily move its attendant register wheel to a new indicating position. The registered result will depend .upon the adjusted projection of the stop 63 and the like for each spring member, the spacing and number of teeth on each actuated gear, and the length of travel of the actuating rod. As arranged in this disclosed embodiment, the register elements are placed .equi-distant from the joint of the housings 10 and 30, and thelengths of the actuating spring members are equal. Only the relative outward extension of the spring members, the number and spacing of teeth in the respective ratchet wheels and the position of the disengaging lips are different. As the reciprocal longitudinal movement of the actuating rod moves the spring members of the ratchet means into contact with the .gears, one or more, or sometimes all the register wheels, will be moved one notch. Should the movement of the actuating rod be less than that required to' mitting limited engagement can be made, only those portion of this form of the calipering device, the register wheels and attendant gear wheels are positioned in housing 30 as by pivots 68, 70, 72 and 74 respectively. A detent arrangement including a ball 76, a spring 78 and a set screw '80 let into the housing 30 to cooperate with each register assembly maintains the registered indication of the wheels until further actuation thereof by operation of the device or in resetting'for another calipering operation. 7

Operation of the above described registering caliper will be limited to the examination of tubing sections'supported on a rack. This is the particular use for which the device is. designed, but is not its sole or limiting purpose. Preliminarily, the register wheels are normally set to their zero position. -A pulling cable or red is pushed through a section or joint of tubinglying on the rack. Therassembled device is attached to the depths of interior defects desired to .be measured will-be registered. Using the illustrated device asan example, the tooth spacing of the four ratchet wheels'is selected at .15", .1", .085" and .05". 'Pits in the tubing permitting the outward movement of the feelers to correspond with the lesser of this tooth spacing will move that ratchet wheel only. It will be evident, however, that deeper;

pits extending the movement of. the actuating rod. 26. will move the ratchet wheel set to respond to that particular depth as well as all wheels set for lesser depths, making the reading cumulative on the shallower reading wheels. No more than one geartooth or varc will be registered,v however, because of the lateral posiitoning of the actu-. ating leaf springs'relative to the ratchet wheels of the registers by 'means of stops like 63 and which permit the spring member to engage one tooth only for each successive longitudinal reciprocation before disengagement by the lip structure.

As the deeper pits are registered not only on the register of comparable response, designed by construction and adjustment to receive and indicate such a pit, but also by those indicating lesser depth pits as explained, it is necessary to subtract from each separate register the reading of the next larger tooth register to obtain the correctresulth Figure 4 illustrates a typical reading showing the four registers indicating only two readings of one depth'in the length of calibrated tubing. From the above discussionof the accumulation feature of the register combined withthe caliper of this device, it will be evident that this indication on only one of the four registering elements shows, the defect-to be two pits of the minimum registerable depth only. i

A different reading .is shown in Figure 5. Reading from left to rightthe registers indicate 24 l1 -6--3. This means that in all thelength of tubing .calipered there are 24 pits or'depressions which can be registered by :the device. Of the 24 indicated by the ratchet means responsive to the depth of the least pit, 3 are of the deepest measurable depths; 3 more (6 minus 3) are of a lesser depth; 5 more (11 minus 6) are next to the shallowest to be registered, leaving a total of 13 (24 minus 11) as the sum of the shallowest type to which the devicev is sensitive. I

The above description of one form of the invention and its operation will make clear the two alternate forms of registering means shown in Figures 6 and 7 of the drawing. As previously noted, the above described device operates by reason of the toothed wheels of the ratchet means having different sized teeth for each wheel arranged at different circumferential spacings. The leaf spring actuators are all the same length and operably used in that way. These alternate forms of the device vary the length of the leaf spring actuators, keeping the register assemblies at equal distance from the end of the device (Fig. 6), or vary the longitudinal positions of the registers relative to each other, keeping the leaf spring actuators of equal length. Such arrangement permits limiting the relative movement of the respective ratchet assemblies for accurate registering. Additional- 1y, it will be'evident after reading the detailed description of the first described device, that each form has advantages and disadvantages primarily from the viewpoint of manufacture. All will register the movement of the feelers, registering the calipering action as previously described.

Figure 6 shows the leaf spring actuators as of different lengths and additionally adjustable in length by slotting the same where fastener screw 60 secures them to actuating rod 26. Because of this difference they are distinguished from those in Figure 2 by adding a prime to the numbers, thus 52, 54', 56 and 58'. By making these actuators additionally adjustable in length and controlling the lateral positioning by means of the stops 63 and 65 previously described, accurate operation is attained. The ratchet wheels (also primed to distinguish from those in Figure 2) 44',46, 48' and 50 positioned and functionally like those previously described have an equal number of equally sized and spaced teeth. It will be recognized that these two differences from the originally described device make no change in the operating func- I tion, nor the result.

From what has been said for the devices disclosed in Figures 2 and 6, Figure 7 is readily understood. In this figure the actuating leaf spring elements of Figure 2 being of equal length are used in cooperation with the ratchet wheels of Figure 6, all of which are equally toothed. The operating result is achieved by varying the spacing of the registers, longitudinally of the register housing 30, to indicate movements of different lengths on the registering wheels.

It will be evident from the above two examples of registering taken together with the description of the device and its operation in its several forms, that a registering caliper for rapid and accurate determination of the re-usability of tubing is disclosed. The mechanism is rapid in use and immediately indicates results. No dissembly to reveal a chart is necessary in any of its individual forms and no electrical connections or costly cables are required.

The invention claimed is:

1. An internal tube wall caliper comprising a housing, a plurality of independently movable feelers mounted circumferentially of said housing, feeler motion transmission means common to all said feelers, a plurality of registers in said housing each responsive to a different degree of movement of said motion transmission means, and means connecting said registers individually with the motion transmission means.

2. An internal tube wall caliper comprising a housing, a plurality of independently movable feelers mounted cir- 6 cumferentially of said housing, feeler motion transmis= sion means common to all said feelers, a plurality of registers mounted to display indicia through apertures in said housing and'being progressively responsive to different degrees of movement of said transmission means,

and individual connecting means between the registers and said feeler motion transmission means.

3. An internal tube wall calipering device comprising a housing, a plurality of independently movable feelers circumferentially mounted in said housing, means for individually urging said feelers outwardly of said housing, feeler motion transmission means common to all feelers and mounted for reciprocal movement in the housing in response to the feeler movement, registering means operably supported at apertures in said housing to permit reading of same, and selective ratchet means in operable engagement with each of said registering means adapted to respond to differences in the extent of the reciprocal movement of the feeler motion transmission means.

4. An internal tube wall calipering device comprising a housing, a plurality of independently movable feelers circumferentially mounted in said housing, means for-individually urging said feelers outwardly of said housing, feeler motion transmission means common to all feelers and mounted for reciprocal movement in the housing in response to the feeler movement, a plurality of registering wheels rotatably supported at apertures in said housing to permit reading of same, and ratchet means for each of said wheels operably connected to respond to the reciprocal movement of the feeler motion transmission means.

5. The calipering device of claim 4 further characterized by said ratchet means for each of said registering wheels being adapted to respond to a different degree of movement of the feeler motion transmission means.

6. The calipering device of claim 5 further characterized by said ratchet means including a ratchet wheel of dilferent sized teeth and tooth spacing for each registering wheel and actuating elements of equal length operatively extending between the feeler motion transmission means and each of said ratchet wheels.

7. The calipering device of claim 5 further characterized by said ratchet means including a ratchet wheel of the same sized teeth and tooth spacing for each of the registering wheels and actuating elements of difi'erent lengths operatively extending between the feeler motion transmission means and each of said ratchet wheels.

8. The calipering device of claim 5 further characterized by the ratchet means adapted to respond to different degrees of movement of the feeler transmission means being a plurality of ratchet wheels spaced longitudinally at different distances in the housing from the circumferentially mounted feelers, each ratchet wheel having an equal number of teeth and tooth spacing and engaged by actuating elements of equal length operatively extending between the feeler motion transmission means and each of said ratchet wheels.

9. Register means for use with tubing calipers having independently movable feelers circumferentially spaced about a housing and a reciprocable motion-transmitting means in operating cooperation with said feelers, comprising a plurality of cylindrical registers operably mounted in visual position relative to said housing, and selected ratchet means for each register operably connected to the reciprocable motion transmitting means whereby each register isoperated in response to a different degree of movement of the transmitting means.

References Cited in the file of this patent UNITED STATES PATENTS 

